Absorption refrigerating machine



June 1929- E. WlRTH-FREY ABSORPTION REFRIGERATING MACHINE Filed March 14, 1924 Patented June 25 1929.

UNITED STATES PATENT OFFICE.

ELIAS WIRTH-FREY, 0F AARAN, SWITZERLAND, ASSIGNOR TO SULZER FRERES SO- GIETE ANONYME, OF WINTERTHUR, SWITZERLAND, A CORPORATION OF SWITZER- LAND.

ABSORPTION REFRIGERATIN G MACHINE.

Application filed March 14,1924, Serial No. 699,159, and .in Germany April 19, 1923.

This invention relates to an absorption refrigerating machine comprising a generator-- absorber, an evaporator and a condenser, and has for its primary object to prevent overfilling the evaporator and filling up the condenser with liquid and also to avoid the possibility of the generator being emptied and the heater going dry. Further objects of the invention are to prevent solution from being forced back out of the generator-absorber through the suction or absorption pipe into the evaporator, during the expulsion period, and to prevent a back-flow of refrigerant from the evaporator through the pressure or expulsion pipe into the generatorabsorber after the heat is cut off and during the absorption period.

In the absorption refrigerating machine according to the present invention the eondenser and the evaporator are both disposed at a higher level than. the generator-absorber, the condenser is further arranged above-the evaporator, there is further provided a pressure or expulsion pipe connecting the generator-absorber and the condenser, connecting means between the condenser and the evaporator, a suction or absorption pipe connecting the evaporator and the generator-absorber, and a by-pass passage between the evaporator and the generator-absorber.

Thepressure pipe is conveniently provided with a resistance, which may be produced by providing this pipe with a liquid seal or by leading the pipe up to a suflicient height above the condenser or by both means simultaneously. The resistance in the pressure pipe is preferably divided up into a number of partial resistances. ceivers may be provided in the pressure pipe to contain liquid trapped therein, consecutive receivers being connected together by by-pass passages each containing a liquid seal, whilst a further by-pass passage is preferably provided to connect one ofthe end receivers with the evaporator or the suction line. An enlargement may be provided at the upper end of the portion of the pressure pipe containing a liquid seal.

' The absorption or suction pipe may also be provided with an automatically operating resistance device, either by utilizing the hydrostatic pressure resulting from a suitably chosen difference in level between the Thus one or more re-- evaporator and the generator absorber, or by leading the suction pipe up to a sufficient height above the evaporator. The by-pass passage being in the form of a liquid seal preferably opens into the gas-filled space in the generator-absorber.

Figures 13 by way of example some constructions according to the invention.

The known constructions are open to ob jection in that it is necessary to provide external mechanical means whereby the liquid residues collecting in the evaporator can be discharged therefrom. Moreover these constructions are not provided with safety devices which come into operation if the cooling devices fail to act or which operate to prevent a complete evaporation of thewhole contents of the generator-absorber, so that with electric heating it is possible for example for the heating element to burn out.

These known machines have a further disadvantage when the. suction pipe is separate from the pressure pipe in that when operat- 1ng automatically solution may be forced out of the generator-absorber through the suction pipe into the evaporator during the expulsion period, or a back-flow through the pressure pipe may occur after the heat is cut ofi and during the absorption period.

With the machine according to the present invention on the other hand, overfilling the evaporator and filling up the condenser with liquid is rendered impossible by the setting up of a liquid circulation. Again should disturbances of any kind occur in working, such for example as when the cooling devices fail to act or when the heat is not cut off, a liquid circulation is set up and the heater is prevented from going dry. Moreover the construction of the suction and pressure pipes may be such as to prevent solution from being forced into the evaporator during the expulsion period, or refrigerant from being alat a higher level than the generator-absorber.

The gases expelled from solution by heating the generator-absorber 1 pass through the pressure pipe 4 into the condenser 2 where 60 The accompanying drawings illustrate in they are liquefied in the known manner by the action of a cooling medium. The pressure pipe 4 may be valve controlled, if desired. From the condenser 2, in front of which maybe provided a water separator not shown, the liquid refrigerant passes either directly or past a controlling valve through a pipe 6 into the evaporator 3, where the refrigeration action takes place by withdrawing from the surroundings' the heat necessary for vaporizin the refrigerant. When the heat is cut 05 from the generator-absorber 1 and cooling devices therein are brought into action, the Vaporized refrigerant is absorbed through the suction pipe 7 in consequence of the reduced pressure resulting from the cooling action. The evaporator 3 is in communication through a by-pass passage 8 with the generator-ab her 1, so that any excess of liquid hefrigEM solvent, which tends to overfill the evapora r, can flow, back into the generator-absorber.

- In order to prevent solution .from being forced from the generator-absorber 1 into the evaporator 3 during the expulsion period, the

suction pipe 7 is provided with a resistance device which produces a resistance which in order to be elfective,-must be greater than the total resistance in the pressure pipe 1 taken -up to the junction of the two pipes in front v a suitably chosen difference in level between the evaporator 3 and the generator-absorber 1.

The figures show constructions in which the pressure pipe 4 is provided with a resistance device, for the purpose of preventing back flow of refrigerant from the evaporator or the condenser through the pressure pipe into the generator-absorber after the supply of heat to the generator is cutoff and during absorption. i

In the Figures 1 nd 2 this resistance is produced by leadi g the pressure pipe 4 to a height above the condenser 2. This pipe contains a liquid seal formed by the pipe 9, which is provided at its upper end with an enlargementlO and is connected at its lower-end to a receiver 11. The receiver 11 is connected to the suction pipe'7 through a by-pass passage 12. The arrangement of the suction pipe 7 in this construction is the same as that shown in Figure 1 with the exception that the by-pass passagelS opens into the suction p1pe. "When gas starts to flow back along the 'the said suction pipe, and

pressure pipe. 4 towards the generator-absorber, the liquid in the ,receiver 11 is forced up into the tube 9, which acts as a liquid seal and prevents the back flow of the gas. The

receiver 11 always remains full of liquid since I it is supplied with fresh liquid during each expulsion period up to the level of the bypass passage 12.

In Figure 3 the resistance in the pressure pipe 4 is divided up into a number of partial resistances arran ed in series. Each partial resistance 1s pro need by means of a pipe 9 which has an enlargement 10 at its upper end and is connected at its lower end to a receiver 11, consecutive receivers being connected together by means of by-pass passages 12 each formed to contain a liquid seal. The last receiver 13 is connected through a by-pass passage 14 directly tothe evaporator 3, so that the liquefied refrigerant does not miss its evaporation. The receivers 11 or the pipes '9 may be provided with non-returnvalves,

if desired, in order still further to increase the safety factor. The arrangement illustrated in Figure 3 has the advantages that the height of the machine'can'be' reduced and;

that greater security of operation isensured,- since any irregularities in working are more effectively damped out by the numerous enlargements than would bepossible with the arrangement shown in Figure 2.

It will be understood that the invention is not limited to the arrangements illustrated and that modifications may be made without departing from the scope of the invention.

I claim:

1. In an absorption refrigeratin machine, the combination with a generator-absorber of i an evaporator disposed at a higher level than the-gererator-absorber, a condenser arranged above" the evaporator, an expulsion 0r pressure pipe connecting the generator-absorber and,the condenser, connecting means between the condenser and the evaporator, a suction or absorption pipe connecting the evaporator and the generator-absorber, the said pressure pipe branching separately from the said suction pipe, and an unobstructed continuously open overflow device between the said evaporator and the said generator-absorber.

2. In an absorption refrigerating machine, the combination witha generator-absorber of an evaporator disposed at a higher level- *than the generator-abs0rber, a: condenser arranged above the evaporator, an expulsion or pressure pipe connecting the generator-absorber andflthe condenser, connecting means between the condenserand the evaporator, a suction or absorption pipe connecting the evaporator and the generator-absorber, the said pressure pipebranching separately from an unobstructed continuously open overflow device which cons nects the lowest part of the evaporator and i I the generator absorber.

3. In an absorption refrigerating machine, the combination with a generator-absorber of an evaporator disposed at a higher level than the generator-absorber, a condenser arranged above the evaporator, an expulsion or pressure pipe connecting the generator-absorber and the condenser. connecting means between the condenser and the evaporator, a suction or absorption pipc connecting the evaporator and the generator-absorber, the said pressure pipe branching separately from the said suction pipe, and a by-pass passage between the said evaporator and the said generator-absorber, and means including a liquid seal in said expulsion pipe for forming an automatically operating resistance to the flow of fluid therethrough.

4. In an absorption refrigerating machine the combination with a generator-absorber of an evaporator disposed at a higher level than the generator-absorber, a condenser arranged above the evaporator, an expulsion or pressure pipe connecting the generator-absorber and the condenser, connecting means between the condenser and the evaporator, a suction or absorption pipe connecting the evaporator and the generator-absorber, the said pressure pipe branching separately from the said suction pipe,'and an unobstructed continuously open overflow device between the said evaporator and the said generatorsabsorber, expulsion pipe, a receiver connected with said enlargement containing a liquid forming a column between said enlargement and receiver, thus forming means to seal the expulsion pipe during the absorption period and to direct the flow of gas through the absorption; pipe into the generator-absorber.

5. In an absorption refrigerating machine the combination with a generator'absorber of an evaporator disposed at a higher level than the generator-absorber, a condenser ar ranged above the evaporator, an expulsion or pressure pipe connecting the generatorabsorber and the condenser, connecting means between the condenser, and the evaporator, a suction or absorption pipe connecting the evaporator and the generator-absorber, th

said pressure pipe branching separately an enlargement in saidfrom the said suction pipe, an unobstructed continuously open overflow device between the said evaporator and the said generatora receiver connected with said enlargement containing a liquid forming a column between said enlargement and receiver, and a further by-pass passage connecting the receiver to the suction pipe.

6. In an absorption refrigerating machine, the combination with a generator-absorber of an evaporator disposed at a higher level than the generator-absorber, a condenser arranged above the evaporator, an expulsion or pressure pipe connecting the generator-absorber and the condenser, connecting means between the condenser and the evaporator, a suction or absorption pipe connecting the evaporator and the generator-absorber and an unobstructed continuously open overflow device between the evaporator and the generator-absorber, said absorption pipe being shaped to utilize the hydrostatic pressure resulting from a suitable difiei'ence in level between the evaporator and the generator-absorber for forming an automatically operating resistance to the flow of fluid through said pipe.

7 In an absorption refrigerating machine,

the combination with a generator-absorber of an evaporator disposed at a higher leved than the generator-absorber, a condenser arranged above the evaporator, an unobstructed continuously open overflow device between the evaporator and the generator-absorber, an expulsion or pressure pipe connecting the generator-absorber and the condenser, connecting means between the condenser and the evaporator, a suction or absorption pipe connecting the evaporator and the generatorabsorber an enlargement in said expulsion pipe, a receiver connected with said enlargement and containing a liquid adapted to vary its level and to form a column between said enlargement and receiver and means to allow the liquid, to flow back from the receiver through the suction pipe into the generatorabsorber.

In testimony whereof -I have aflixed my signature.

ELIAS WIRTH-FREY. 

